To evaluate some intelligent method for decision-making we need to compare the method against the competing methods to get some idea of its performance and capabilities. In everyday practice this is enough and the method, if proven good, can be used for different problems. In medicine however we have a demand for the best solution in all circumstances. It is therefore impossible to declare one method as acceptable for every type or even every single problem. In this article we would like to stress some important aspects of machine learning in medicine, especially the creation of specific decision models. We believe the evolutionary concept is a good approach to this as it creates many diverse solutions.